"Demi spends most of her time in Idaho, not L.A.," the source explains. At issue? The girls are tired of "walking on eggshells," around Moore, 49, who went to rehab in February after her painful November 2011 split with Ashton Kutcher after six years of marriage (and his highly publicized affairs).

At Tallulah's June 7 high school graduation, says a witness, Moore sat away from her family, "didn't speak to them," and left before her daughter got her diploma.

When Moore announced the end of her marriage to Kutcher, 33, last November, she made a brief reference to her girls. "As a woman, a mother and a wife there are certain values and vows that I hold sacred, and it is in this spirit that I have chosen to move forward with my life."